The present invention relates to a medical operation simulation system. More particularly, the invention relates to a medical operation simulator and a method of controlling the simulator. The simulator enables an operator to simulate a medical operation by manipulating an imitation instrument provided on an operation input device, thereby moving a virtual instrument in a virtual space, with respect to a three-dimensional image constructed from slice images formed by means of X-ray CT, MRI, MRA or the like, and which displays the positional relation between a region of interest and each virtual instrument moving as the operator operates the operation input device.
A medical operation may be simulated and navigated by using slice images such as X-ray CT images, MRI images or MRA images. The simulation and navigation thus performed are important since they help operators to plan procedures for operations to be performed or to support operators to perform operations.
In the present specification, operative navigation performed during actual operations will be called "simulation," too.
Simulation and navigation are effected by using slice images which have been formed at regular intervals. Important regions and anti-invasive regions, such as the affected parts, the blood vessels and the nerve, are extracted from the slice images and visualized. The simulation assists the operator, enabling him or she to move the virtual instruments without touching the virtual anti-invasive regions.
A method of performing operative navigation is known, as disclosed in Jpn. Pat. Appln. No. 8-10266. In the method, the positions of the instruments being used in an operation are detected, slice images that correspond to the instruments are selected, and patterns indicating the positions of the instruments are displayed and superimposed on the slice images. And an alarm is generated when any instrument approaches a critical region.
To accomplish more realistic simulation it is effective to display three-dimensional images. The three-dimensional images displayed reduce the visual discrepancy between the real regions and instruments, on the one hand, and the virtual regions and instruments, on the other. Thus, more correct simulation can be carried out.
In the conventional method described above, medical instruments only are displayed and superimposed on the slice images. No three-dimensional images are displayed. This makes it difficult for operators to grasp the three-dimensional relationship between the position of each instrument and the position of any region.
In the conventional method, an alarm is generated when any instrument comes within a predetermined distance from an anti-invasive region. However, it is impossible to determine minute changes in the distance between the instrument and the region.